for the instructor Energy part 2 covers alternative energy for generating electricity using hydro-power and stored energy start slide show with next slide

Energy

Alternative Sources of Energy Electrical Energy Hydroelectric (dams, turbines, tidal, ocean currents, etc.) Stored Energy Nuclear Energy Wind Energy Solar (multiple sources) Biomass/Algae Require more investment in U.S. power grid WHY?

Electrical Energy Alternatives Hydroelectric I - Dams Advantages of Dams Existing form of energy production (2.4 % in the U.S.) Have a very low relative cost to operate (<½ coal) Do not produce hazardous by-products (waste or air pollution) Once built can have a very long life decades or longer Reservoir can be used for recreation purposes & irrigation Stored water is a constant energy source

Electrical Energy Alternatives Hydroelectric I - Dams Disadvantages of Dams Expensive to build, especially if they are to last (sediment issue) Impact large area upstream (reservoir – people & wildlife) Jurisdiction issues on rivers between adjoining states/nations Rise of local water table is possible Interruption of sediment flow on rivers Impact on flushing of water pollution

Niagara Falls, USA Hydroelectric Dams

Three-Rivers Gorge Dam, China Sediment build-up behind this dam is of special concern But it will produce electricity for 100 million people

Three-Rivers Gorge Dam Environmental Impact Baiji, Yangtze River Dolphin Siberian Crane

Electrical Energy Alternatives Hydroelectric II - Dams Of the 80,000 dams in the U.S. only ~3% are used to generate electricity. Though expensive to build, dams that generate electricity are relatively inexpensive to operate – therefore the U.S. is missing a large opportunity to use an already expensively built resource.

Electrical Energy Alternatives Hydroelectric II - Dams Though expensive to build, dams that generate electricity are relatively inexpensive to operate – therefore we are missing a large opportunity here to use an already expensively built resource. New York State has over 600 registered dams, not including many associated with the lock system on the barge canal. Most do not generate electricity but could be retrofitted to capture this energy source.

Electrical Energy Alternatives Stored Energy I – Pumped Stored Hydroelectricity Utilization of water pumped to higher elevation to store energy for periods of high demand.

Electrical Energy Alternatives Stored Energy I – Pumped Stored Hydroelectricity During periods of low electrical demand excess (low Cost) electricity can be utilized to run pumps to store water at higher elevation, and then during periods of higher demand the water is released and electricity is produced through turbines in the system.

Electrical Energy Alternatives Stored Energy I – Pumped Stored Hydroelectricity Due to energy losses in the turbines and during pumping this system is a net energy consumer, but if run correctly will run at a net profit.

Electrical Energy Alternatives Hydroelectric II - Tidal Usually involves creation of ‘tidal-dams’ or free standing turbines in estuaries to capture flow and drive turbines Advantages Do not produce hazardous by-products (waste or air pollution) Located in areas that are otherwise not being utilized

Electrical Energy Alternatives Hydroelectric II - Tidal Disadvantages Relatively costly to build & cost to operate is variable Would be limited to coastal regions, and only those with relatively large tidal fluctuations Has intermittent energy production (though this is completely predictable) Can impact organisms that live in these areas (especially those associated with estuaries – which generally have larger tidal effects)

Examples of Tidal Energy Production Tidal energy dam in La Rance, France; 240 MW

Electrical Energy Alternatives Hydroelectric III – Ocean Currents A potentially very important source of electrical energy Currently it is only speculative in nature